Why is Canada's wildfire smoke blanketing parts of North America? - explainer

Wildfire smoke from Canada has blanketed large parts of North America, creating orange-hued skies and prompting health warnings. This phenomenon is becoming a regular occurrence as rising global temperatures contribute to massive forest fires, particularly in Canada's vast northern forests.

Canada currently faces more active wildfires than in the past two years, and the total area burned so far this year surpasses the 10-year average. Forest fires are a natural process, but their size and intensity have increased significantly in recent years. Climate change leads to drier forests, which accelerate fire spread. Experts like Mike Flannigan, a professor of wildland fire at Thompson Rivers University, note that the area burned in Canada has nearly quadrupled since the 1970s, with warmer temperatures prolonging the wildfire season and increased lightning strikes also igniting fires.

Andrew Dessler, a climate scientist at Texas A&M University, attributes the current situation to climate change, stating that "nothing else has changed" to cause such intense blazes. He explains that these fires often occur in largely unmanaged forests where they were historically allowed to burn out. As fires grow larger and scorch more forest area, the resulting smoke travels with the wind. Fires in northern and western Ontario, along with northern Minnesota, have caused the world's worst air quality in cities like Toronto, and the smoke has since spread to New York, Washington, Detroit, and Chicago.

Governments are implementing measures to protect communities, including closing forest areas to the public. However, the scale of the fires, fueled by climate change, presents a significant challenge to managing air quality and environmental health across the continent.

“

The reason this is having a big effect on the U.S. right now is because of climate change; that’s the thing that has changed. Nothing else has changed.